Day to day with 4 week old baby

Okay mommies, I know this might be a silly question but I'm a sahm and I am wondering what everyone does with their babies at this age? He sleeps, eats and cries if he isn't being held. We do tummy time for a few minutes in the evening and I sing to him and read books after he eats during the day but what else is there to do? Am I doing enough? Weather has been rainy so we haven't been able to go for walks. He doesn't like his swing so alone time for him doesn't last very long. Needing to feel like I'm doing more for him I guess...